Hello there, and thank you for posting your question here on brainly.
The diameter of a circle is how long it is from the left side of the circle to the right side.
The radius of a circle is the length of either the left or the right side to the middle.
So, the radius is half of a radius.
You can divide the known diameter by 2 to get your answer.
Its diameter is 25.
Divide 25 by 2.
25 / 2 = 12.5
Its radius is 12.5 in.
That would be answer choice A.
Hope this helped!! ☺♥